In the past, 9-1-1 emergency services (911) determined the home address of a caller based on the caller's home telephone number. Today, mobile telephones provide their current latitude and longitude coordinates in the event of a 911 call through either a Global Positioning System (GPS) chip or triangulation between cell towers. However, a growing trend is users who rely on in-home modems with voice capabilities (often Voice-over Internet Protocol or VoIP) for their voice communications instead of, or in addition to, traditional wireline telephones, wireless telephones, and mobile telephones.
Issues arise when a caller dials 911 using a modem with VoIP service because a VoIP adapter can be plugged into any broadband internet connection. As a result, the caller could actually be hundreds or even thousands of miles away from their home address. However, the 911 call goes to an answering point associated with the caller's home address and not the caller's actual location. Even if a GPS receiver is installed in the VoIP modem, it will likely be indoors and unable to get a signal. Presently, 911 callers using a modem with VoIP service must verbally verify their location when summoning assistance in an emergency.